// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef UI_BASE_MODELS_LIST_MODEL_OBSERVER_H_
#define UI_BASE_MODELS_LIST_MODEL_OBSERVER_H_

#include <stddef.h>

#include "ui/base/ui_base_export.h"

namespace ui {

class UI_BASE_EXPORT ListModelObserver {
public:
    // Invoked after items has been added to the model.
    virtual void ListItemsAdded(size_t start, size_t count) = 0;

    // Invoked after items has been removed. |start| is the index before the
    // removal.
    virtual void ListItemsRemoved(size_t start, size_t count) = 0;

    // Invoked after an item has been moved. See ListModel::Move() for details
    // of the arguments.
    virtual void ListItemMoved(size_t index, size_t target_index) = 0;

    // Invoked after items has been changed.
    virtual void ListItemsChanged(size_t start, size_t count) = 0;

protected:
    virtual ~ListModelObserver() { }
};

} // namespace ui

#endif // UI_BASE_MODELS_LIST_MODEL_OBSERVER_H_
